Synthesis of Advanced Ceramics in the Systems Si-B-N and Si-B-N-C Employing Novel Precursor Compounds

1992 ◽  
Vol 271 ◽  
Author(s):  
H.-P. Baldus ◽  
O. Wagner ◽  
M. Jansen
Keyword(s):  
Liquid Ammonia ◽  
Single Phase ◽  
Chemical Properties ◽  
Primary Amines ◽  
The Novel ◽  
Physical And Chemical Properties ◽  
New Materials ◽  
Soluble Polymers ◽  
Physical And Chemical ◽  
And Chemical Properties

ABSTRACTThe reaction of Cl3Si-NH-Si(CH3)3 with BCl3 yields the novel compounds Cl3Si-NH-BCl2 and (Cl3SiNH)2-BCl. The ammonolysis of these monomeric precursors in liquid ammonia gives rise to highly crosslinked borosilicon imides. Pyrolysis of the polymeric imides in a stream of ammonia at 1250°C yields amorphous borosilicon nitrides with formal compositions of Si3B3N7 and Si6B3Nu respectively. MAS-NMR, DTA/TG, SEM and TEM investigations reveal that the resulting materials are single phase.The reaction of the novel precursors with primary amines yields meltable and soluble polymers suitable for producing fibers or coatings. Subsequent pyrolysis in NH3 leads also to amorphous borosilicon nitride. The physical and chemical properties of the new materials will be discussed.

Review of Physical Properties and Preparation of Nano-Superconducting Materials

2013 ◽  
Vol 816-817 ◽  
pp. 65-69
Author(s):  
Yi Zhang
Keyword(s):  
Transition Temperature ◽  
Chemical Properties ◽  
Material Research ◽  
Physical And Chemical Properties ◽  
Superconducting Transition ◽  
New Materials ◽  
Preparation Methods ◽  
New Material ◽  
Physical And Chemical ◽  
And Chemical Properties

New materials play an important part in today high and new technology.Superconducting nanomaterial has become the most vibrant in new material research due to its unique physical and chemical properties. This paper focuses on how small-size effect affects superconducting transition temperature, and summarizes the concrete preparation methods of superconducting nanomaterials, hoping to provide a reference for material researchers.

Adsorption of Pollutants from Water with Carbon Nanotubes

2013 ◽  
Vol 634-638 ◽  
pp. 192-197
Author(s):  
Jiang Yan Li ◽  
Ying Xiang Jiang
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Properties ◽  
The Novel ◽  
Physical And Chemical Properties ◽  
Inorganic Pollutants ◽  
Adsorption Performance ◽  
Environmental Material ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Structure Of Carbon Nanotubes

The unique morphology and structure of carbon nanotubes (CNTs) keep attracting a great number of researchers to explore the novel properties of these materials. The special structure of CNTs determines its physical and chemical properties, mainly reflected in its novel electrical, mechanical properties and excellent adsorption performance. This review summarizes the adsorption properties of CNTs and their properties related to the adsorption of various heavy metal ions, organic and inorganic pollutants from large volumes of aqueous solutions. CNTs is a kind of potential environmental material. This article also put forward future opportunities for CNTs application in environmental systems.

scholarly journals Preparation of Graphene Materials and Their Applications in the Field of Electrochemistry

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Qing Liao ◽  
Tingting Song
Keyword(s):  
Electrochemical Method ◽  
Carbon Nanomaterials ◽  
Preparation Method ◽  
Chemical Properties ◽  
Modern Society ◽  
Physical And Chemical Properties ◽  
New Materials ◽  
New Type ◽  
Physical And Chemical ◽  
And Chemical Properties

In the development of modern society, many new materials and technologies have been integrated into the development of various industries. As a new type of two-dimensional carbon nanomaterials, graphene has great advantages in physical and chemical properties and is widely used in various fields of development. Among them, the electrochemical method is one of the important ways to prepare graphene materials, which has the characteristics of quickness and environmental protection, and can effectively produce a large amount of high-quality graphene and its composite materials. Based on this, the paper introduces the preparation method of graphene materials and studies the application of graphene materials in the field of electrochemistry.

scholarly journals Structure and physical properties of silkworm cocoons

2012 ◽  
Vol 9 (74) ◽  
pp. 2299-2308 ◽  
Author(s):  
Fujia Chen ◽  
David Porter ◽  
Fritz Vollrath
Keyword(s):  
Physical Properties ◽  
Chemical Properties ◽  
Gas Permeation ◽  
Physical And Chemical Properties ◽  
Woven Composite ◽  
New Materials ◽  
Fibre Composites ◽  
Wide Range ◽  
Physical And Chemical ◽  
And Chemical Properties

Silkworm cocoons have evolved a wide range of different structures and combinations of physical and chemical properties in order to cope with different threats and environmental conditions. We present our observations and measurements on 25 diverse types of cocoons in a first attempt to correlate physical properties with the structure and morphology of the cocoons. These two architectural parameters appear to be far more important than the material properties of the silk fibres themselves. We consider tensile and compressive mechanical properties and gas permeation of the cocoon walls, and in each case identify mechanisms or models that relate these properties to cocoon structure, usually based upon non-woven fibre composites. These properties are of relevance also for synthetic non-woven composite materials and our studies will help formulate bio-inspired design principles for new materials.

Comparison and Analysis of the Flow Rate

2015 ◽  
Vol 669 ◽  
pp. 197-204
Author(s):  
Marek Prislupčák ◽  
Anton Panda
Keyword(s):  
Flow Rate ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
New Materials ◽  
Production Time ◽  
Construction Design ◽  
Machine Parts ◽  
Comparison And Analysis ◽  
Physical And Chemical ◽  
And Chemical Properties

Separation of materials is a fundamental technology for the production of machine parts. Division is involved in the overall use of the material and also impact on the overall production time. With the development of new materials increasing requirements for the construction, design and durability. This makes the development of new materials with higher mechanical, physical and chemical properties. These materials are difficult to machine, and this gives rise to the development of non-conventional technologies, which include water jet technology.

ZnO/ZnS (hetero)structures: ab initio investigations of polytypic behavior of mixed ZnO and ZnS compounds

2018 ◽  
Vol 74 (6) ◽  
pp. 628-642 ◽  
Author(s):  
Dejan Zagorac ◽  
Jelena Zagorac ◽  
J. Christian Schön ◽  
Nemanja Stojanović ◽  
Branko Matović
Keyword(s):  
Ab Initio ◽  
Density Functional ◽  
Local Density ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Density Approximation ◽  
New Materials ◽  
Functional Theory ◽  
Physical And Chemical ◽  
And Chemical Properties

The range of feasible ZnO/ZnS polytypes has been explored, predicting alternative structural arrangements compared with previously suggested or observed structural forms of ZnO/ZnS compounds, including bulk crystal structures, various nanostructures, heterostructures and heterojunctions. All calculations were performed ab initio using density functional theory–local density approximation and hybrid Heyd–Scuseria–Ernzerhof functionals. Specifically, pure ZnO and ZnS compounds and mixed ZnO1–x S x compounds (x = 0.20, 0.25, 0.33, 0.50, 0.60, 0.66 and 0.75) are investigated and a multitude of possible stable polytypes for ZnO/ZnS compounds creating new possibilities for synthesis of new materials with improved physical and chemical properties are identified.

scholarly journals Viability of Cupola Slag as an Alternative Eco-Binder and Filler in Concrete and Mortars

2021 ◽  
Vol 11 (4) ◽  
pp. 1957
Author(s):  
Israel Sosa ◽  
Pablo Tamayo ◽  
Jose A. Sainz-Aja ◽  
Ana Cimentada ◽  
Juan Antonio Polanco ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Properties ◽  
Recovery Process ◽  
Amorphous Structure ◽  
Environmental Costs ◽  
Physical And Chemical Properties ◽  
New Materials ◽  
Limestone Filler ◽  
Physical And Chemical ◽  
And Chemical Properties

Obtaining new materials capable of meeting society’s demands motivates the search for new solutions that are capable of satisfying twofold requirements: respect for the environment and obtaining more durable and resistant materials. Cupola slag is a by-product generated in the process of obtaining ductile iron. When the slag undergoes rapid cooling, its vitrification is favored, leaving the silica in an amorphous structure and, thus, susceptible to reacting. Through reaction, the slag can develop cementing properties and cement can consequently be partially replaced with residue, providing savings in economic and environmental costs compared to traditional hydraulic binders. In this study, the physical and chemical properties of cupola slag and its recovery process are analyzed. Mortars that incorporate traditional admixtures (fly ash and limestone filler) have been manufactured and consistency and mechanical properties have been compared with mortars that incorporate cupola slag admixture. Mortars have also been manufactured with normalized sand and with Portland cement replacements (0, 10, 20, and 30% by weight) with cupola slag, and both the consistency and the mechanical properties have been compared at 7, 28, 60, and 90 days. The results obtained show the suitability of cupola slag as a binder and as an admixture, with respect to the traditional ones, and how the mechanical properties tend to converge for all of the replacement levels characterized, for ages close to 90 days of age.

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

Response of corn (Zea mays L.) to various organic-based fertilizers in marginal upland of Sta. Rita, Samar

2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno
Keyword(s):  
Block Design ◽  
Management Strategies ◽  
Chemical Properties ◽  
Organic Fertilizers ◽  
Growth And Yield ◽  
Physical And Chemical Properties ◽  
Total N ◽  
Randomized Complete Block Design ◽  
Physical And Chemical ◽  
And Chemical Properties

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.

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